PEG Conjugated Antibodies

BOC Sciences has established technology development services that include proven PEGylation processes, purification processes, determination of quality standards & key process parameters, and subsequent formulation development of products. We offer PEG antibody conjugation services and antibody purification processes to our customers.

Fig.1 PEGylated antibody. (Lin et al., 2016)

What is PEG Antibody?

PEG conjugated antibodies are complexes formed by covalently conjugating a polyethylene glycol (PEG) molecule to an antibody. This conjugation process can alter the properties and functions of the antibody and is often used to improve the performance of antibodies in drug discovery and therapeutics. PEG antibodies are usually prepared chemically, most commonly by chemically reacting the PEG with the active site (e.g., the amino or thiol group) of the antibody to form a covalent linkage. The size of the PEG molecule and the binding mode can be adjusted to obtain the desired properties of the PEG antibody.

Antibody PEGylation Advantages

• Improved Stability

PEG modification enhances the stability of antibodies, making them more resistant to temperature, pH and proteases. The polyethylene glycol shell provides a protective layer that reduces degradation, aggregation and inactivation of the antibody. This is important for the stability of the antibody during storage, transportation.

• Reduced Immunogenicity

PEG modification reduces the immunogenicity of an antibody, decreasing its recognition and clearance by the immune system. The PEG masks the surface features of the antibody and reduces interaction with the immune system.

• Increased Bioavailability

PEG antibodies can improve bioavailability in vivo by increasing the molecular size of the antibody and altering its physicochemical properties. This can affect the distribution of the antibody in tissues, targeting and the binding affinity of the antibody to the target.

PEG Antibody Conjugation

BOC Sciences provides PEGylation services to obtain PEGylated antibodies to the target through various modifications, such as N-terminal modification, sulfhydryl modification, and carboxyl modification.

• N Terminal PEGylation

First, appropriate functional groups are introduced at the N-terminus of the PEG compounds, which are designed to react with the N-terminal amino group of the antibodies. Then, in order to expose the N-terminal amino group of the antibody, it is usually necessary to remove the Fc region of the antibody. Subsequently, the activated PEG compound is reacted with the antibody with the Fc region removed to achieve PEG modification of the N-terminal amino group. Currently, we adopt the targeted modification of the N-terminal amino group, which can effectively maintain the original biological activity of the drug.

• Sulfhydryl PEGylation

Combined with our advanced technology, we can introduce sulfhydryl group or some specific groups into the pre-determined site of the antibody, and then carry out the modification of the group, so as to obtain the fixed-point modification product with higher retention of activity and reduced immunogenicity.

• Carboxy PEGylation

By modifying the carboxyl group of the antibody with a polyethylene glycol derivative with a hydrazide activating group, a targeted modification product can be obtained.

PEGylated Antibody Purification

After completing the PEGylated antibody, purification of the antibody is required, and a suitable purification solution can be selected based on the nature of the product and the application.

• Gel filtration Chromatography: PEGylated antibodies have a higher molecular weight and will remain in the pores of the gel column for a longer period of time, thus separating them from small molecule impurities.
• Affinity Chromatography: PEGylated antibodies can be selectively enriched using PEG-conjugated resins (e.g. Hydrazide-PEG resin) or PEG-conjugated structural domains.
• Reverse-phase Chromatography: PEGylated antibodies are typically more polar and can be separated from smaller, non-polar solvents by reverse-phase columns.

Our Advantages

• Strong background and expertise in PEG chemistry
• Innovative and novel PEG technology, and advanced equipment
• Ensure fast, efficient and optimized PEG conjugated Antibodies
• Analytical HPLC and MS analyses are performed in every development cycle.
• Cost-effective and high-quality PEGylated products

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